Portable shot-ribino device



D. C. GENTRY. PORTABLE SHOT FIRING DEVICE.

APPLICATION FILED APR.2. I918.

Patented May 20,1919.

INSULH ION kifidrneys DEMAUS C. GENTBY, OF VINCENNES, INDIANA.

PORTABLE SHOT-FIRING DEVICE.

Specification of Letters Patent.

Patented May 20, 1919.

Application filed April 2', 1818. Serial No. 228,207.

To all whom it may concern Be it known that I, DEMAUS C. GENTRY, a citizen of the United States, residin at Vincennes, in the county of Knox and tate of Indiana, have invented certain new and useful Improvements in Portable Shot-Firin Devices; and I do hereby declare the fofiowing to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to shot firing devices and more particularly to a portable apparatus of this character, efe-rably for use in gaseous coal mines, an the primary object of the invention is to provide an inexpensive device which can be conveniently operated from an electric current carrying wire,vsuch as an e ectric light or power wire.

A further object of the invention is to provide a shot firing device embodying a plurality of time controlled circuit making contacts and means for controlling the admission of electric current to said contacts.

A still further object of the invention is to provide a shot firing device embodying a carbon or otherbrush and a plurality of such contacts for successive engagement with the brush to close the shot firing circuits successively, said brush and contacts by virtue of their composition resisting adhesions when engaged with each other while the explosive is being fired by the shorting of the circuit.

A st1ll further object of the invention is to removably position the shot firing mechanism within a casing which will prevent the admission of gases to the apparatus and thus eliminate the possibility of an explosion therefrom.

A still further object of the invention is to arrange fuses between the carbon or other contacts and the shot firing wire binding posts which will prevent the blowing of the fuses in the main line in case of a short in the circuit of the shot firing wires.

A still further object of the invention is to provide means for limiting the rotatable movement of said time controlled contacts, allowing ample time or intermission between shots.

With these and other objects in view as will appear as the description proceeds, the invention comprises the various novel features of construction, combination and arrangement of parts as will be fully described hereinafter and afterward specifically claimed.

Referring to the drawings,

Figure 1 represents a side elevation of the device, v

Fig. 2 represents a view of the mechanism removed from the casing, and the wiring connected thereto.

Fig. 3 represents a transverse sectional View showing the contacts.

Fig. 4 represents a transverse sectional. view showing the fuses of the contacts, and

Fig. 5 represents a sectional elevation of an improved shot firing cap.

In order that the construction and operation of the invention may be readily comprehended by those skilled in the art to which the invention relates, Ihave illustrated an approved embodiment thereof in the accompan ing drawings and will now proceed to ful y describe the same in connection with said drawings in which 1 is a portable casing provided with a suitable handle and into which the apparatus may be inserted and removed whereby access may be had to the mechanism.

The apparatus is mounted upon a base board 2 of insulation attached to and supported by the end board 3, which also is of suitable insulating material. This end board serves 'to close the open endof the casing and is adapted to be secured thereto by a hasp 4 on each side.

5 is an alarm clock attached on the base board and provided with a laterally extending stop. 6. A key shaft 7 is connected to the alarm key arbor of the clock and connected to rotate with it. 8 is an -arm that projects laterally from the key shaft and is adapted to engage the stop 6 to limit the rotation of the key shaft to one revolution. As shown, the key shaft extends through the end board 3 and is provided with a wing nut 9 to enable the apparatus to be rewound or set after each operation.

A plate or dial 10 of insulating material is fixed on the key shaft 7 and is provided circumferentiall for three fourths of its circumference wit a plurality of carbon or other contacts 11 s aced apart adjacent the periphery of the p ate.- Each of these contacts is connected by a fuse 12 to an adjacent binding post 13 arranged on the side of the plate 10 opposite to that on which the contacts 11 are positioned. Each binding post 13 has a shot firing wire 14 connected to it andto a corresponding binding post 15 on the end board 3, enough slack being left in said wires to permit the dial to freely rotate one revolution.

These contacts 11 are adapted to be 5110- electric current line wire 19 which may be' any convenient current carrying wire in the immediate vicinity in which it is desired to use the shot firing device, suchfor instance as an electric light or power line wire. Fuse plugs 20 of higher fusibility than the fuse wires 12 are placed in the line wire 19. A wire 21 connects the switch 18 with the brush 16.

In Fig. 5 will be seen a detail View of an improved form of cap which comprises two pieces of adhesive or other fabric 23 and 24 securely fastened together'over the terminal ends of the shot firing wires, which latter are connected by a low fusible resistance wire 25. This cap is primarily designed for use in connection with the old fashioned black powder and will efi'ectively explode the powder by sending a current through the cap suificient to blow the low fusible resistance wire.

In the operation of the apparatus each shot to be fired has one of the shot firing wires 14 connected to it by a wire 26 and the return wire 27 so that when the switch 18 is closed and the contacts 11 are revolved to successively engage the brush 16, the circuits will be closed in successive order. When it is desired to set the'apparatus, the key shaft 7 is turned, until the arm 8 comes into engagement with the stop 5 which action will rotate the plate 10 until the brush rests in the one fourth circumferential space between the contacts. The switch 18 is then closed. When the alarm goes oflf' and the shaft 7 begins to revolve, the contacts 11 will be brought into successive engagement with the brush '16 to complete the shot firing circuits in succession. Theshaft will revolve until it again engages the stop 6 which will limit the rotation of the plate 10 to one revolution.

After all the shots have been'fired, the switch 18 can be opened and the devicerewoundor set by turning the thumb nut19; It is to be ofcourse understood ,that any number of contacts may be used-tosuit the a ation of the invention, together with the device which I now consider to be the best embodiment thereof, I desire to have it understood that such changes in construction and arrangement of parts may be made when desired as are within the scope of the appended claims.

Having I claim as new is 1. A portable shot firing device embodying a supporting member, an arcuate series of contacts carried by said member, a brush to successively engage said contacts, said member and brush being mounted to rotate relatively to bring the contacts into successive engagement with the brush, a time controlled mechanism for rotating said member and brush'relatively, an arcuate series of binding posts carried by said member adjacent to said contacts and arranged in pairs description taken in.

thus described my invention what therewith, individual fuse Wires bridging the contacts and binding posts, and wires connected to and leading from said binding posts for connection with firing caps.

2. A portable shot firing device embodying a casing, a closure therefor, a base secured to sa1d closure and extending within the casing, an alarm clock mounted on the base, a shaft connected to theclock and extending through said closure, a plate secured on said shaft between the clock and closure, a brush carried by the base, an"arcuate series of contacts carried by said plate to successively engage said brush, binding posts carried by said closure for the connection of wires of several firing circuits, and flexible wires connecting said binding posts with the 7 contacts and brush and disposed around said shaft between said closure and base. A,

In testimony whereof I have signed my name to this specificationin the presence of two subscribing witnesses:

v DEMAUS C. GENTRY.

Witnesses:

' EUGENE Bowers,

MARGARET DRISKELL. 

